The present disclosure relates to video editing devices which are connected to a network and can communicate with an external terminal typified by a camcorder.
High-speed wireless communications have in recent years been becoming available in urban areas, which are typified by widespread use of Worldwide Interoperability for Microwave Access (WiMAX) or 4G/Long Term Evolution (LTE). As a result, it has become practical to upload digital data, such as photographs, videos, etc. captured using a digital camera or a digital video camera, to an online service, such as a cloud service etc., through wireless communications.
For example, Japanese Unexamined Patent Publication No. 2005-168056 describes a camera which includes a data communication unit which transfers image data of a subject and identification data corresponding to the image data, a captured frame storage unit, and a transfer image data storage unit. As a result, the user can upload captured image data to an online service provided by a photographic shop etc., and therefore, it is not necessary for the user to hand a recording medium to a photofinisher, i.e., it is not necessary to put time and effort into ordering printing etc. Thus, the convenience of transferring photographs or videos to a server on the Internet is considerably beneficial to users.
On the other hand, International Patent Publication No. WO01/060062 describes a video recording device which compresses a video signal to simultaneously generate high-resolution video data and low-resolution video data, stores the high-resolution video data to a recording medium provided in the device, and wirelessly transmits the low-resolution video data to a separate editing device. This document also describes that the user performs editing by a separate editing device using the low-resolution video data, and only an edited list obtained as a result of the edition is wirelessly written to the recording medium provided in the video recording device. This technique has been made based on the fact that when video data is to be transferred, the size of high-resolution video data to be recorded is considerably large compared to the transfer rate of wireless transmission which is widely available at present.
For example, as of 2013, the effective upload rate in using a 4G/LTE network which is a wireless communication network available within a relatively wide area in Japan is not more than about 2-15 Mbps, while the bit rate of video data to be recorded which is widely used in the broadcasting business is about 25-200 Mbps. In other words, it is not currently practical to transfer all video data to be recorded to a server on the Internet using a wireless network. This is why the video recording device described in International Patent Publication No. WO01/060062 above transfers low-resolution video data separately generated from the same video source instead of high-resolution video data to be recorded.
Japanese Unexamined Patent Publication No. 2008-199677 describes a video broadcasting system which is connected to a video camera, and simultaneously generates high-resolution video data and low-resolution video data, transfers the low-resolution video data to a receiver terminal through a network, and in addition, in response to a retransmission request from the receiver terminal, broadcasts high-resolution video data of a video which starts a predetermined time before the time of receiving the video retransmission request. As a result, the user can check all video data transmitted from a camera located at a remote place, and obtain high-resolution video data of only a portion which the user has determined by the checking is necessary, through a network. For example, the convenience of this system is more obvious in the case where a video camera is used during news gathering while a receiver terminal is provided in a broadcast station. Videos used in news programs mostly have a time length of as short as about 30 seconds to several minutes. However, it is necessary to check the entire video in order to find the necessary portion. However, it takes a lot of time to bring a video camera from a place where news gathering is performed back to a broadcast station, and therefore, it is necessary to transfer a video from the video camera to the broadcast station through a network. To do so, low-resolution video data is generated and transferred. However, the low-resolution video data has poor definition when it is displayed on a television. Therefore, information related to a necessary portion is sent from the receiver terminal back to the video broadcasting system, so that high-resolution video data of only the necessary portion is obtained. The transfer range is limited only to a necessary portion. Therefore, even if the transfer rate of a wireless network is low, the transfer can be expected to be completed within a practical period of time.
A video editing device will be discussed which operates in cooperation with a video camera which has a function of recording high-resolution video data to a recording medium included therein, and a function of transferring low-resolution video data generated simultaneously with the high-resolution video data to a server etc. through a network.
As described above, the user browses through low-resolution video data transferred from the video camera using the video editing device, to specify a necessary range of a video. The video editing device sends information about the specified range back to the video camera through a network, so that high-resolution video data of that portion is transferred from the video camera to the video editing device.
However, here, a problem arises that when information about a necessary range of a video is sent back from the video editing device, the corresponding high-resolution video data does not necessarily exist in the video camera.
Commonly used video cameras mostly have a removable recording medium to which a captured video is recorded in a video file format. Examples of a widely used recording medium include Secure Digital (SD) memory cards and Blu-ray (registered trademark) Disc Rewritable (BD-RE) media, and P2 cards and Professional Disc media for video cameras used in the broadcasting business. These recording media can be removed from a video camera after recording has been finished.
A video camera and a video editing device are highly likely to be located at places which are physically separated very far from each other. Therefore, it is difficult for a user who is operating the video editing device to find a state of a recording medium inserted in the video camera, and it is also difficult for a user who is operating the video camera to know when a request for high-resolution video data will be sent from the video editing device.
Specifically, when a video editing device requests a video camera to transfer high-resolution video data, then if a recording medium storing the desired video data has been removed from the video camera, the video editing device cannot obtain the high-resolution video data. Also, the recording medium is not necessarily connected to the same video camera, and may be inserted in a different video camera.
When the recording medium itself is subsequently obtained, a portion including only low-resolution video data may be replaced with high-resolution video data. However, for example, particularly when only some of a plurality of specified ranges have not been successfully obtained, it takes a lot of time and effort for the user to manually manage or determine which of the ranges has not been successfully obtained.